Gravity

[BlameTheEx]

TeleMad

 

I am still short of time, but here goes.

 

you say: "And we know from Einstein's principle of equivalence that acceleration and gravity are indistinguishable"

 

Er yes. with the caveats that Einstein may yet be proved wrong, indistinguishable does not mean having the same causes, and that this equivalence is limited to the points of view of an observer in a gravity field and an observer being accelerated (not observers watching from elsewhere).

 

This equivalence is not particularly useful, as it does not allow the observers to relate to the rest of the universe. It is a local equivalence only.

 

As far as it goes, I am happy with this principle, because it in no way effects my arguments. I claimed the time and C were reduced inside a gravitational field FROM THE VIEWPOINT OF AN OUTSIDE OBSERVER. Not that Einstein's principle can be stretched to include such an observer, but even if it could I would still be happy. An outside observer observers time dilation for an object that is accelerated, and that time dilation is indistinguishable from that of gravity, but this is a matter of effect, NOT cause.

 

We have no real understanding of the cause of gravitational time dilation, although we have measured the effect with considerable accuracy. A valid way of describing the cause may well be, as I claim, a reduction in C. This particular principle of Einstein's does not rule it out.

 

At a fundamental level all particles are waves, or standing waves, acting at the speed of light. Reduce C, and you reduce the speed of all actions and interactions in proportion so effectively that nobody would notice without reference to a place outside the area of your reduction. Reducing C Is the equivalent to dilating time. More than equivalent at a guess. I would say that Time passes at the speed of C.

 

An object travelling at relativistic speeds can be thought of as travelling at exactly the same speed as a stationary one. They are both travelling at the speed of C but the stationary object is travelling at this full speed in the direction of time. The other is travelling mostly in space, with a lower component of velocity in the direction of time.*

 

The situation inside a gravitational field is different. The velocity in the direction of time is reduced, but there is no component of velocity in space. C itself appears to have been reduced. If I am right, that is because C HAS been reduced.

 

 

 

* For this to be true there must be a valid direction for time, that is independent of the velocity of any local objects. The accepted view is the direction of time in which the observer is travelling However I would like to throw in the possibility that there IS a locally valid direction for time independent of not only local objects, but also the observer. I am NOT claiming that there is a direction for time that is consistent for the entire universe.

[TeleMad]

BlameTheEx: you say: "And we know from Einstein's principle of equivalence that acceleration and gravity are indistinguishable"

 

Er yes. with the caveats that Einstein may yet be proved wrong,

 

Er, why not just chuck all of science out then? Wait a minute, you are already half there! You want to dismiss the principle of equivalence that general relativity rests largely upon, and you want to dismiss the constancy of the speed of light, which special relativity rests largely upon.

 

Wow, who would have thought that an unknown, posting on this particular site, would overthrow two of the pillars of modern physics! Amazing!!

 

BlameTheEx: … indistinguishable does not mean having the same causes, and that this equivalence is limited to the points of view of an observer in a gravity field and an observer being accelerated (not observers watching from elsewhere).

 

Yeah, so? That’s the whole point. The observer in the strong gravitational field is undergoing a great acceleration, as the equivalence principle tells us.

 

And guess what. It necessarily follows that the observer outside that strong gravitational field is NOT undergoing that great of an acceleration. Thus, the large difference in the strength of the gravitational fields is equivalent to a large difference in the two observers’ accelerations.

 

As the material I quoted from Brian Greene explained, the equivalence between gravity and acceleration along with the difference in the strength of the gravitational field is what causes “meter sticks” on the surface to be length contracted when viewed from the outside, and therefore, what causes the distance to be effectively doubled. And this effective doubling explains your paradox without violating any pillars of modern science (unlike your ‘explanation’, which violates special relativity).

 

BlameTheEx: This equivalence is not particularly useful,

 

I guess not for you, since it refutes you :-)

 

BlameTheEx: As far as it goes, I am happy with this principle, because it in no way effects my arguments.

 

Wrong, it refutes your arguments (which were already refuted by special relativity…double refuted…not a great argument to stubbornly hold onto).

 

BlameTheEx: I claimed the time and C were reduced inside a gravitational field FROM THE VIEWPOINT OF AN OUTSIDE OBSERVER. Not that Einstein's principle can be stretched to include such an observer,

 

Says who? You? You’re wrong (no surprise there, by now).

 

Go back and read Brian Greene’s statements above. Note how the observer INSIDE the Tornado ride and the observer OUTSIDE the Tornado ride measure differently. And why? Because length contraction occurs from the viewpoint of the outside observer, looking in at another observer undergoing a greater acceleration (and remember that Einstein’s principle of equivalence).

 

BlameTheEx: … We have no real understanding of the cause of gravitational time dilation…

 

Wrong again. Gravitational time dilation is caused by differences in acceleration, just as length contraction is. See again the material I quoted from Brian Greene.

 

BlameTheEx: A valid way of describing the cause may well be, as I claim, a reduction in C.

 

No, that is not valid. It violates special relativity.

 

When one explanation violates a repeatedly confirmed scientific principle, and another follows naturally from the confirmed scientific principles, which explanation do you think needs to go bye-bye? Yep…yours.

 

BlameTheEx: This particular principle of Einstein's does not rule it out.

 

This particular principle of Einstein’s EXPLAIN

[BlameTheEx]

TeleMad

 

"Wow, who would have thought that an unknown, posting on this particular site, would overthrow two of the pillars of modern physics! Amazing!"

 

You are beginning to get sarcastic. If your next post is not more polite I will not reply to it. If you consider having that as the last word is a victory it will be a victory of being ignored for your bad language, not because you have proved your point of view.

 

Still, for now I continue. I will just ignore your replies that are limited to bluster, depreciation, and simple denial.

 

You say: "Yeah, so? That’s the whole point. The observer in the strong gravitational field is undergoing a great acceleration, as the equivalence principle tells us." "Wrong again. Gravitational time dilation is caused by differences in acceleration, just as length contraction is. See again the material I quoted from Brian Greene"

 

But this observer is NOT undergoing acceleration. He is standing on the surface and not moving in any particular direction other than (if you accept it as a direction) Time. Regardless, It is not acceleration that dilates time, but velocity. Gravity may be the equivalent of acceleration, but its undeniable that our observer has no velocity. If you claimed that this equivalent of acceleration resulted in an equivalent of velocity you still have a problem. The equivalent of acceleration never stops, so the equivalent of velocity must keep growing, and time dilation will steadily increase!

 

You say: "When one explanation violates a repeatedly confirmed scientific principle, and another follows naturally from the confirmed scientific principles, which explanation do you think needs to go bye-bye? Yep…yours."

 

Er not necessarily. The principle is that C is invariant. True, but exceptions don't prove scientific rules, they break them. And there IS an exception. This rule, as generally accepted, is broken by black holes which will apparently accelerate objects to ABOVE C. My explanation has, at least, the virtue of being self consistent, as it does not predict singularities.

 

The confirmation of scientific principles here are in my favour. Gravitational time dilation has been confirmed, and so have gravitational lenses. C is apparently reduced just the way it is in a glass lens. That is the evidence. Put a gravitational field in the way, and it takes longer for light to arrive. You can argue that gravity creates more distance for light to travel in, but there is no evidence to favour that theory over that of gravity reducing C.

 

You say: "And if your anti-scientific explanation were correct, we’d see double the time dilation and length contraction as that predicted by Einstein’s theories…there’d be Einstein’s, and there would be yours. Yet we don’t get this double-the-expected amount. Guess what that means? You are wrong: Einstein is right".

 

Yes, I AM predicting double time dilation, but I would be surprised if Einstein didn't do the same. I feel I can do so as it is simple logic. We know that an object resting inside a gravitational field is (at least in effect) time dilated. We know that velocity also (again at least in effect) dilates time. For an object dropping into a gravitational field these 2 effects will have to be added (using the Lorents transform if necessary). For an object given just enough velocity to escape the gravitational field they will cancel each other out.

 

As to this theory being unscientific, it is not. It explains the evidence in a very simple manner. It contradicts no evidence that I know of. It leeds to no breakdowns of self consistency. Those are all the rules of a good theory bar one. It needs to be proved.

 

This theory can only be considered unscientific from the viewpoint of opposing generally held opinions in the scientific community, but to search for better answers is not unscientific, but the spirit and essence of science.

 

Ok. I have lots to do. Our correspondence is doing wonders for clarifying my ideas on this topic,

[TeleMad]

TeleMad: Wow, who would have thought that an unknown, posting on this particular site, would overthrow two of the pillars of modern physics! Amazing!"

 

BlameTheEx: You are beginning to get sarcastic.

 

Because you've already become pigheaded and antiscientific - you're as bad as a young-Earth creationist now, and I have no patience with that type of "science".

[TeleMad]

BlameTheEx: If your next post is not more polite I will not reply to it.

 

Who cares? Actually, you'd be doing us all a favor. Your ceasing to post your anti-scientific "theories" - which violate pillars of modern physics - will be a gain for the site, not a loss.

[TeleMad]

BlameTheEx: You say: "Yeah, so? That’s the whole point. The observer in the strong gravitational field is undergoing a great acceleration, as the equivalence principle tells us." "Wrong again. Gravitational time dilation is caused by differences in acceleration, just as length contraction is. See again the material I quoted from Brian Greene"

 

But this observer is NOT undergoing acceleration. He is standing on the surface and not moving in any particular direction other than (if you accept it as a direction) Time.

 

Showing your ignorance again, I see.

 

When viewed from general relativity, that observer IS accelerating.

 

"With special relativity, Einstein proclaimed that absolute spacetime provides the benchmark [for motion], but special relativity does not take account of gravity. Then, through the principle of equivalence, Einstein supplied a more robust benchmark that does include the effects of gravity. Since gravity and acceleration are equivalent, if you feel gravity's influcence, you must be accelerating." (emphasis in original, Brian Greene, The Fabric of the Cosmos: Space, Time, and the Texture of Reality, Knoph [Publisher], 2004, p67)

 

 

And he continues...

 

"Einstein argued that only those observers who feel no force at all - including the force of gravity - are justified in declaring that they are not accelerating. Such force-free observers provide the true reference points for discussing motion, and it's this recognition that requirs a major turnabout in the way we usually think about such things." (emphasis in original, Brian Greene, The Fabric of the Cosmos: Space, Time, and the Texture of Reality, Knoph [Publisher], 2004, p67)

[TeleMad]

BlameTheEx: It is not acceleration that dilates time, but velocity.

 

If you say so....now, do you know the definition of acceleration? Acceleration is the rate of change in...guess what....yep, velocity. So if two observer's constant acclerations differ, then their velocities must differ (more precisely, only at one instant in time could their velocities be identical).

 

BlameTheEx: Gravity may be the equivalent of acceleration, but its undeniable that our observer has no velocity

 

No, they do...from an general relativity perspective. They must, since their accelerations differ.

 

BlameTheEx: If you claimed that this equivalent of acceleration resulted in an equivalent of velocity you still have a problem. The equivalent of acceleration never stops, so the equivalent of velocity must keep growing, and time dilation will steadily increase!

 

Wrong again. You're starting to look really stupid. You'd server yourself well just to shut up and go away.

 

READ AGAIN THE ORIGINAL MATERIAL I QUOTED FROM BRIAN GREENE! NOTE HOW ALTHOUGH THEIR ACCELERATIONS DIFFER, EACH OBSERVER'S VELOCITY REMAINS CONSTANT. THUS, THEIR RELATIVE VELOCITIES DO NOT CHANGE OVER TIME - THUS, TIME DILATION DOES NOT STEADILY INCREASE.

[TeleMad]

I could go on and show how virtually every one of your statements is flawed, but I've got to go to work now.

 

Take my advice. Leave now before I completely crush you!

[BlameTheEx]

TeleMad

 

What a berk, Ok you have this room all to yourself. What you going to do now, scream insults at the walls?

[Freethinker]

OK guys, let's try to bring this in line or we will need to ban or close the thread down. Is there some way you two can start with some fundamental aspects and work out the details? And both side use valid verifyable data to support claims. I won't point fingers, but we do expect all sides to be supported with facts here.

 

The most repeated items seem to be acceleration vs velocity. Gravity as an issue.

 

Can someone start by suggesting some defintions so we are sure we are using the terms the same? Then we can step to interactions, such as acceleration "simulating" gravity (Einstien's elevator thought experiment). Only later to bring in outside viewers as we build the discussion.

 

Let's build from the bottom up rather than throw the whole thing in and try to rip it down.

 

And in this corner...

[TeleMad]

BlameTheEx: What a berk, Ok you have this room all to yourself. What you going to do now, scream insults at the walls?

 

No...unlike you, the walls don't continue to argue against logic and science.

 

I envisioned us as playing a game of chess: a battle of wits with two opponents trying to show that his own position is superior. But you blundered from the beginning and wouldn't admit it. So I pressed on and found your king exposed. I called mate-in-1 on you and instead of your resigning, you claimed it wasn't there. So I showed you by mating you. And what did you do? You moved your king like a knight, jumping over chess pieces in the process, and then claimed you never were in mate. As I would in a chess game, at that point I knew you weren't a worthy opponent...at that point, I lost all respect for you.

[TeleMad]

We can start with this.

 

First, BlameTheEx seems to be confused about some of the very basic terms of motion.

 

1) Speed. This is a scalar quantity (has magnitude, but no direction) and is distance (another scalar quantity) divided by time.

 

2) Velocity. This is a vector quantity (has both magnitude and direction). Velocity and speed are not the same thing: speed is the, well, speed half of velocity (the other half being direction). So velocity can change even if speed doesn't.

 

3) Acceleration. This is the rate of change in velocity. Note that since velocity is a vector, then velocity can change by an object (a) changing speed (either an increase or a decrease), (B) changing its direction of motion, or © changing both its speed and its direction of motion.

 

Now on to the relativity stuff.

 

Plain old special relativity tells us that the greater the difference in speed between two observers in uniform motion, the greater the degree of time dilation and length contraction.

 

Tangential speed is the speed of an object rotating about a fixed point, and varies with distance from the center. For example, a person pressed against the wall of the Tornado ride has a greater tangential speed than a person near the center when they each make a full turn in the same time. Tangential speed is tied to accelerated motion, since the object of interest is not moving in a straight line (even though it is moving at constant speed, in our example).

 

If one observer (who obviously is at rest in his own reference frame), such as a person outside the Tornado ride, sees another person moving with a large tangential speed, such as another person pressed against the inner wall by inertia, then the stationary observer will note time dilation and length contraction (in the direction of instantaneous motion) when viewing the other person’s reference frame. This is shown by logic and by the quote from Brian Greene. Note that the degree of time dilation and length contraction are calculated the same way as in special relativity, using the relativistic gamma factor.

 

Thus we see that this kind of constant acceleration (change in direction of motion, by rotating about a fixed point, while maintaining a constant speed) produces time dilation and length contraction (as seen by an observer not undergoing that same motion), with the degree of the difference in time and length intervals being tied to the difference in speeds, and being calculated using the same factor (the relativistic gamme factor) used in special relativity.

 

So we can see that time dilation and length contraction occur when:

 

1) Two observers in uniform motion are moving relative to one another.

 

OR

 

2) One observer, at rest, considers another observer that is undergoing constant acceleration (rotation about a point) at a constant tangential speed. This is exactly the example the Brian Greene quote used.

 

OR

 

3) Two observers are each undergoing constant acceleration (rotation about a point) at constant tangential speeds, but their tangential speeds differ.

 

There may be other cases, but these are enough to make the point.

 

Now, by Einstein’s principle of equivalence, (3) is indistinguishable from two observers experiencing different-strength gravitational fields. Thus, when one observer is “outside” a strong gravitational field while another is deep inside of it, the “outside” observer will see both time dilation and length contraction occurring in the other observer’s reference frame.

 

And for BlameTheEx's setup, which supposedly showed that light had slowed to 0.5c, this length contraction effectively doubles the distance the light on the surface travels, thus making a calculation for the speed of light produce c…the exact answer we are supposed to get.

 

PS: Another interesting quote (since it shows BlameTheEx to be wrong on something he said)…

 

“… as Einstein argued eloquently

[Uncle Martin]

I am not a trained physicist, just a lay person with an interest in understanding the universe in which we exist. My hope is to learn something from these(especially this) discussions. TeleMad and Blame', could I bother you both for a bit of personal info? Would you please tell me something of your backgrounds? If I, as a lay person is to weigh two differing viewpoints, it would be helpful to know of your qualifications to make these claims. I would also ask that you resolve your current standoff, as I'm sure that many others wish to learn more from both of you. This has been a very good thread so far, let us keep it going. Thank you both for what has been posted, and hopefully for what is to come.

[TeleMad]

Here are some facts about the exchanges...

 

1) BlameTheEx claims that physics shows taht black holes can't form. That immediately raised a red flag for a lot of us since it goes against scientific consensus.

 

Note that BlameTheEx does not limit his statements ot just the singularity - he made this clear. It is a black hole - not the singularity - which he claims physics shows cannot form.

 

Also, BlameTheEx doesn't deny that black holes can exist. His argument already sounds like a Creationist argument. Life exists but the laws of nature show that life can't arise from non-life...therefore, God must have created life. Black holes exist but the laws of physics show that they can't be formed...therefore, God must have made them.

 

2) BlameTheEx claimed that the best way to think about gravity is as a slowing of the speed of light. Another reason we should all be wary of his statements since this one violates special relativity.

 

3) BlameTheEx claimed that if one observer were on the surface of a massive body and another observer werr out in space looking down - and the graviational time dilation made time pass twice as slowly on the surface relative to the outside observer - that either (1) the speed of light must be reduced to 1/2, or (2) the distance must be doubled, leading to black holes supposedly having infinite radii.

 

THIS CONCLUSION OF HIS WAS QUITE SIMPLY WRONG. Those are not the only two possiblities, and in fact, both can be dismissed without much thought. Science has the explanation, a third possiblity BlameTheEx didn't know even exised, and it "falls out" naturally from the theories of relativity. I spend a good amount of time - invested a lot of effort - into explaining that: the distance remains the same, but the "meter sticks" are reduced by half, thus effectively doubling the distance. This shoudl have ended the debate.

 

That should have cinched it. But then BlameTheEx tried to wiggle out by saying that the concepts I brought up applied only to special relativity, in which the observers are moving relative to each other. I then spent more time tracking down and typing out Brian Greene's explanation for why this is not so. By showing that the length contraction I discussed applied in BlameTheEx's example, I tied up all the lose end.

 

This SURELY should have ended the debate. Yet it didn't. BlameTheEx - in typical Creationist style - refused to listen to logic, continued to put forth ideas that violate well-supported pillars of modern science, and attempted to twist science into fitting his view. His view is right - science needs to bend to meet him.

 

 

So exactly what science is anyone here going to learn from BlameTheEx? That general relativity is wrong? That special relativity is wrong? That black holes can't form? His positions are ANTI-scientific.

[BlameTheEx]

Freethinker

 

Too late. As I have allready made clear. I ain't replying to people who won't be polite. Truth is I am not even reading TeleMad's replies now. Do me a favour, and let me know if he calms down and apologises. Oh, and I would also like news of flying pigs.

[Tormod]

Okay, I enjoyed this discussion for a while, TeleMad had some very decent explanations but this thread is dying now. I say let's close it and move on?

 

Tormod

[katesisco]

Here's something interesting. I found this today: http://www.AIAS.com/us Myron Evans is a Welshman who has developed a new math to accomodate his GUT which so far has led to a new kind of MRI without heavy magnets. I do not pretend to understand the math, I only read fast. It seems from the web that there are quite a few that have offered new theories but of course the test of a theory is being able to make predictions as to future discoveries and/or solutions based on your therory. The current hot topic is how our sun, Sol, interacts with our planetary magnetic field. The article in this month's NG was absolutely thrilling in as much as know so little and have so much to learn. Quite possibly a Unified Theory of Everything is just around the corner, but right now it is interesting to see the sci-fi and imagine that it is real. One site I saw with quite a bit of substantiating material, said that the interreation with the magnetic fields, of which he posed 6 for the Eath at about 30-40 degree latitudes but north and south of the Equator caused massive ejections of radioactive material from the earth's fields of energy and you do have to admit there is OKLO. I like his idea, which is based on the Gaia hypothesus, better than attributing radioactive sites to a nuclear war in the far distant past.